A chromosome containing HOT1 preferentially receives information during mitotic interchromosomal gene conversion.
A chromosome containing HOT1 preferentially receives information during mitotic interchromosomal gene conversion.
复制标题
含有 HOT1 的染色体在有丝分裂染色体间基因转换过程中优先接收信息。
DOI：
10.1093/genetics/124.3.561
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发表时间：
1990
期刊：
影响因子：
3.3
通讯作者：
Roeder,GS
中科院分区：
文献类型：
--
作者：
Voelkel-Meiman,K;Roeder,GS
重组刺激序列HOT1来源于酵母核糖体DNA，与RNA聚合酶I促进转录所需的序列相对应。在携带his4等位基因的二倍体菌株中检测了HOT1对有丝分裂染色体间基因转化的影响。当HOT1被插入到HIS4的两个拷贝附近时，His+重组体的频率增加了大约10倍。当HOT1只存在于两个同源物中的一个上时，重组被加强，并且含有HOT1的染色体上的his4基因优先被转化。在所检测的两对his4异等位基因中，HOT1刺激his4突变的转化，而不是刺激HOT1-近端his4等位基因的转化，而his4突变距离HOT1插入位点更远。与从缺乏HOT1的对照菌株分离的重组体相比，HOT1启动的HIS+重组体在HIS4远端的序列中更多地是纯合的。含有HOT1的染色体上序列的优先转化符合重组的双链缝隙修复模型，表明HOT1促进的基因转化始于HOT1相邻序列中的双链断裂。
The recombination-stimulating sequence, HOT1, is derived from yeast ribosomal DNA and corresponds to the sequences required for promotion of transcription by RNA polymerase I. The effect of HOT1 on mitotic interchromosomal gene conversion was examined in diploid strains carrying his4 heteroalleles. When HOT1 is inserted adjacent to both copies of HIS4, the frequency of His+ recombinants is increased approximately 10-fold. When HOT1 is present on only one of the two homologs, recombination is enhanced and the his4 gene on the HOT1-containing chromosome is preferentially converted. In both pairs of his4 heteroalleles examined, HOT1 stimulates conversion of the his4 mutation which is further from the site of HOT1 insertion more than it stimulates conversion of the HOT1-proximal his4 allele. Compared to recombinants isolated from control strains that lack HOT1, HOT1-promoted His+ recombinants are more often homozygous for sequences distal to HIS4. The preferential conversion of sequences on the HOT1-containing chromosome is consistent with the double-strand-gap repair model of recombination and suggests that HOT1-promoted gene conversion initiates with a double-strand break in HOT1-adjacent sequences.